A majority of available hospital beds designed to keep the patient in the horizontal position is equipped with a positioning patient support, headboards in the head and foot sections of the bed and siderails. Siderails, especially those installed on cribs, must meet several safety requirements. The siderails must cover the entire side section of the patient support in order to prevent the patient from falling, they must enable positioning to at least two positions and, at the same time, they must include a mechanism to lock the siderail in the safe upper position. This mechanism prevents the child patient from disengaging the siderail.
First solutions of the locking mechanism for locking the siderail in the upper position is described, for example, in patent GB152120. Thanks to this solution, the siderail can be moved from the upper to the lower position, where the siderail is approximately at the level of the patient support. However, this mechanism is not absolutely safe, and the siderails might be folded by the patient.
Some of the other problems mentioned above are solved by a mechanism of tubular telescopic siderails which get engaged to each other when the siderail is being folded, and, at the same time, this assembly of mutually engaged siderails can be folded below the level of the patient support. This state of the art has been known for a long time, and it is described, for example, in patent GB637951. This type of siderails, though, can cause an injury to the patient. Another disadvantage of this solution is the fact that manipulation with these siderails can be difficult due to their significant weight.
A frequent issue with the currently used solutions is the already mentioned difficult manipulation with the siderails caused by a reason other than their weight. The siderails are integrated in guide rails of special corner posts. This leads to a problem with balancing the siderails. If the personnel wants to lift the siderail, they must apply balanced force on the upper frame to prevent the siderail from getting stuck. The guide rail limits the range within which the siderail can move. If the siderail is to be folded down to the level of the patient support, the posts with the guide rail must extend below the patient support level. Moreover, the necessity to use such extended guide posts significantly limits the range of elevation of the upper frame with the patient support.
Another solution of the guiding mechanism is described, for example, in patent U.S. Pat. No. 6,772,459, in which a third frame is installed between the upper and lower frame of the siderail, securely mounted to the patient support and limiting the movement of the siderail between the safe upper position and the lower position.
The objective of this invention is to design telescopic siderails in a way that would meet all the above stated safety requirements. On the other hand the corner posts with the guide rail into which the bed siderail is inserted should not limit the lift of the patient support. A siderail should not get stuck in the guide rail under any circumstances, its lowering and lifting should be safe for the patient and as easy and as most comfortable as possible for personnel. Also, a siderail should include a safe mechanism for locking in the upper position that would be very difficult for a child patient to unlock.